塑料加工助剂及配方复习题01.doc

塑料加工助剂及配方复习题01
Plastic processing AIDS and formula problem
One, the noun explanation:
1,plasticizer; It is the substance that adds plasticity in the plastic system and does not affect the intrinsic properties of the polymer.
2,stain; Change the color of the products added in the polymer and improve the cosmetic additives.
3,the heat stabilizer; It is mainly used for PVC and other
chlorine-containing polymers, which will not affect its processing and application, but can also be a kind of auxiliary agent to delay its thermal decomposition.
4,f1ame retardants: Substances that can increase the flammability of materials are called fire retardants.
5,antioxidant: It is a class of chemicals that can be delayed by oxidation of high polymer and ageing.
Light stabilizers; Substances that can inhibit or s1ow the process of photooxygenation are called photostabilizers or uv stabilizers.
7,lubricants: In order to reduce the high polymer internal
friction and external friction. , improve the liquidity of plastic melt, prevent the polymer material in the processing of equipment
in the process of adhesion phenomenon, ensure the products surface finish and add material called lubricant.
8,foaming agent; The foaming agent is a kind of material that can make microporous structure of liquid or plastic in liquid or
plastic state in a certain viscosity range.
9,coupling agent: Coupling agent is a type of substance that can improve the interface characteristics of the packing and polymer materials.
Antistatic agent; Add in resin, fuel or attached on the surface of the plastic products, synthetic fiber, to prevent the polymer materials and liquid fuels of electrostatic hazard chemical additives are collectively referred to as antistatic agent.
11, oxygen index; This is the minimum oxygen required in the nitrogen and oxygen flow when the sample is burned continuously
like a candle.
Foam aid; In the foaming process, those that can adjust and foaming agent and foaming agent decomposition temperature and decomposition rate of the material, or can improve the foaming process, stable foam structure and improve the quality of foam material, can be referred to as foaming agent, or auxiliary blowing agent.
13, tinting strength; Refers to the ability of pigment to affect the color of the whole mixture. The color is large and the dose is small and the cost is 1 ow.
14, hiding power: The ability to stop light from penetrating the tinted product, in other words, is a matter of the size of the stain. The larger the mask, the worse the transparency.
Metal ion passivating agent; A substance that prevents heavy metal ions from causing oxidation to the polymer.
16,anti-reflection agent. A booster that can improve crystal polymer transparency.
17,the plasticizer: introducing a second monomer in polymer polymerization process, because of the second monomer copolymerization in the molecular structure of the polymer, thus reduced the crystallinity of polymer molecular chain. Or the introduction of a branch chain (or branch of a branch) in the polymer chain. And the branched chain can reduce the force between the polymer chain and the chain, thereby increasing the plastic，s plasticity. External plasticizer: the less volatile liquid or low melting solids in addition to the high boiling point in the polymerization system.
Main plasticizer and auxiliary plasticizer; If plasticizer crystallization of polymer molecules can only be inserted into the part of the amorphous region, then this plasticizer is solvent plasticizer, namely auxiliary plasticizer.
If plasticizer can be inserted into the polymer molecules of amorphous regions at the same time can be inserted into the crystallization area, then this plasticizer is solvent plasticizer, which is the main plasticizer.
The efficiency of plasticization; The plasticization efficiency of the plasticizer is called the amount of plasticizer that makes the resin reach a certain degree of softness.
20, main antioxidant and auxiliary antioxidant; The main antioxidant is regarded as a radical cleaner, it through coupling reaction (i. e. termination reaction) or give a hydrogen atom to prevent damaging effects of free radicals in the polymer. The most commonly used antioxides are phenols, followed by amines. The role of an antioxidant is to decompose the peroxide produced by the oxidative polymer oxidation.
Internal lubricants and external lubricants; In order to reduce friction between polymer molecules (internal friction), you need to add lubricants that are compatible with polymers, called internal lubricants.
Lubricants: one kind is in polymer materials processing, the lubricant coating on the surface of the processing equipment, let it melt under the processing temperature, and form a "thin layer" on the metal surface, isolates plastic melt and processing equipment, not adhesion on the device, easy to take off the membrane or roll; Another kind is the compatibility with polymer is very small, in the process of machining easily migrate to the surface, from inside the polymer to form isolation layer material, ingredients to join before processing, make its dispersion in the plastic, and migrate to the surface in the process of machining, the lubrication effect.
2, fill in the blanks:
Analysis of the main factors of plasticization: the intermolecular forces of the polymer, the hydrogen bonding, the crystallinity of the polymer
Theory of plasticizer: lubrication, gel, free volume, etc
Antioxygenation: chain terminated antioxidant (or free radical inhibitor), the main antioxidant; Prophylactic antioxidant (including peroxide dissociation agent, metal ion passivation, etc.) is auxiliary antioxidant. According to structure: amine, phenol, sulfur compound, phosphor compound, organic metal salts etc.
The disadvantage of amines is that they are toxic, polluting, discoloration and their own ease of oxidation. Phenols are
generally less toxic, not discolored, and not polluted. The antioxides of phosphates have the advantages of low toxicity, non-pollution and low volatility.
There are many reasons for the ageing of the polymer materials. Physical factors: light, heat, stress, electric field, rays, etc. Chemical factors: oxygen, ozone, heavy metal ions, chemical media etc. Biological factors include microorganisms, insects, etc.
The heat degradation of PVC resin is a very complicated process,
and there are three kinds of mechanism. Ion mechanism; The
molecular mechanism.
There are three kinds: inorganic flame retardant, halogen flame retardant, phosphor flame retardant, about 45 kinds.
The three elements that sustain combustion: fuel, oxygen, heat. The burning of the polymer can be used for burning speed and oxygen index.
The mechanism of plasticization, interface lubrication and coating
isolation mechanism are accepted
According to its way of producing bubbles in the foaming process, the foaming agent can be divided into two types: physical foaming agent and chemical foaming agent. For chemical foaming agents, two
of the most important technical indicators are the decomposition of temperature and air volume. Common methods for the determination of foaming agent are: differential thermal analysis, thermal
weightless method and so on.
The current widely used antistatic agent is mainly classified as cationic, anionic, non-ionic, amphoteric, and high polymer.
The pigments and pigments used in plastics and rubber are mainly inorganic pigments, organic pigments and dyes.
The mechanism of the coupling agent, using the example of silane or titanate coupling agent, is used to write the corresponding
chemical equation.
Chemical theory: the theory is that coupling agent containing a chemical functional groups, with glass fiber surface silanol groups or other inorganic filler on the surface of the molecular form covalent bonds. In addition, the coupling agent containing at least one other different functional groups and polymer molecular bonding, in order to obtain the good interface bonding, coupling agent is to play a bridge of mutual connection between inorganic and organic facies role. Silane coupling agent general formula can be written
as RSiX3, in which R is reaction with polymer molecules have
affinity and ability of active functional groups, such as vinyl chloride propyl, epoxy group, methyl propylene acyl amine and
sulphur, etc. X is an alkane that can hydrolyze, such as methoxy, ethoxy, etc. Such as ammonium propyl triethoxy silane NH2CH2CH2 - CH2Si (OC2H5) 3, when using it first with inorganic filler (such as glass fiber, etc.), silane hydrolysis into silanol first, then the silicon alcohol-based and inorganic filler surface produces dehydration reaction, in chemical bonds:
In the preparation of composite materials, the Y group of the coupling agent will interact with the organic polymer.
In the end, the bridge between inorganic and organic materials, such as the coupling of epoxy resin. Through the above two reactions, silane coupling agent by chemical bonds combined with improved polymer and inorganic fillers in composite materials, the adhesion between the performance is greatly improved. Titanate coupling agent for filler type thermoplastic polymer and drying, good coupling effect, this kind of coupling agent can use general formula: (R00 (4 - n) Ti (OXR ' Y) n (n = 2, 3). The RO - is hydrolyzable alkoxy short carbon chain, can react with inorganic surface hydroxyl groups, so as to achieve the purpose of chemical coupling; - weather can be a carboxyl, alkoxy, sulfonic group, phosphorus, etc., these groups are important, decided to titanate have special performance.
Four, the analysis problem gives the experiment graph, the analysis experiment result (abbreviated).
7.4.2 extrusion test commonly used experimental extruder, by changing the rotating speed of extruder in the test, to determine the torque of the screw, the screw extrusion side pressure and the amount of change, the typical extrusion test curve as shown in the
figure below.
Curve 3 shows that the lubrication is overdone, the torque is not up, the extrusion pressure is reduced, and the output per minute is down, which is very bad for production.
7. 4. 3 extrusion machine test: one, mixed smelting machine
In the experiment of the mixtures, the torque value of the anti-mixing torque was changed over time. The relationship between the use of stearate and PVC gel time is shown below. As you can see by the picture, with the increase of lubricant additives, mixing the maximum torque resistance reduced when the adding amount of lead stearate increases to 1. 5 " 2. 0%, due to the lubrication excessive plastic compound can，t pack roller, time of arrival in the yield point later, plastic compound gel was incomplete.
What is a plasticizer? What are the main functions of plasticizers? What physical properties will change after adding plasticizers to the polymer? How to change?
Plasticizer is a substance that adds plasticity to the plastic system and does not affect the nature of the polymer.
Plasticizer: the main function of weakening the van der Waals force between the polymer molecules, increase the mobility of the polymer molecular chain, reduce the crystallization of polymer molecule chains, i. e. the increase plastic plastic. The elongation, flexibility and flexibility of plastic have been improved, while hardness, modulus, softening temperature and brittle temperature have all declined.
What are the advantages and disadvantages of the amine and phenol antioxidant? Phenols have excellent discoloration and non-pollution. Because the molecular weight is small, the volatile and the extraction is larger, the anti-aging ability is affected. Amine antioxidant is good,
The biggest drawback is that discoloration and pollution make the polymer change color, limiting its application.
What kinds of non-halogen inorganic f 1 ame retardants? Aluminum hydroxide, magnesium hydroxide, antimony trioxide, boron compounds mainly zinc borate and boric acid barium, phosphorus-containing flame retardants mainly include: red phosphorus (elemental), phosphate, phosphoramide, phosphorus and nitrogen compounds.
What are the pros and cons of lead stabilizers? The main advantages of lead stabilizer: thermal stability, especially long-term heat
and implicit characterization; Good electrical insulation; It has the properties of white pigment, and it is very strong. As an
active agent for foaming agent: Lubricity; Prices are low. The disadvantages of lead stabilizers: poor transparency of the products; Toxicity; Poor dispersion; It is easily contaminated by hydrogen sulfide. Because of the dispersion difference, the
relative density is large, so the quantity is large, often up to five.
What are the categories of light stabilizers according to the mechanism of action? (1) light screening agents, including black carbon, zinc oxide and some inorganic pigments; (2) uv absorbers, including salicylate, diphenylketone, benzene and triazole, substituting acrylonitrile, triazine, and other organic compounds;
(3) the quenched agent, mainly the organic complex of nickel: (4) the free radical capture agent, which is mainly a blocked amine derivative.
What kinds of auxiliaries can be used for chlorinated paraffin? Depending on the amount of chlorine, the effect is different. The chlorine content is more than 70% and can be used as a flame retardant. About 50% of the chlorinated paraffin, which is used as a plasticizer, is mainly used as a lubricant.。